   (fn handler
     ; "return a vector of string explanations ordered oldest to most recent"
     [_ _]
-    (reaction (conj @undo-explain-list @app-explain))))
+    (reaction (undo-explanations))))
 
 (subs/register
   :redo-explanations

  (reset! undo-list [])
  (reset! redo-list [])
  (reset! undo-explain-list [])
  (reset! redo-explain-list []))


(defn store-now!

  []
  (pos? (count @redo-list)))

(defn undo-explanations
  "return list of undo descriptions or empty list if no undos"
  []
  (if (undos?)
    (conj @undo-explain-list @app-explain)
    []))

;; -- subscriptions  -----------------------------------------------------------------------------

(subs/register
